A heating device used to increase an external temperature uses various methods and is used for various purposes.
In particular, among heating devices disposed in an engine room in a vehicle, a heating device that takes charge of interior heating is configured to heat the inside of a vehicle by circulating a heat exchange medium for lowering an engine temperature around a heater core to heat external air.
However, among engines, a diesel engine has a high heat exchange rate and thus requires much time to heat the heat exchange medium cooling an engine at the time of starting the diesel engine, as compared with a gasoline engine.
Therefore, a vehicle with a diesel engine delays heating of the heat exchange medium after the initial starting during the winter season, such that the initial interior heating performance may be degraded.
In order to solve the above-mentioned problems, an air heating heater for vehicles that directly heats air ventilated to the interior side by using various devices has been proposed.
Next, the air heating heater may further improve a heating performance by directly heating air, but occupy a space corresponding to a size of a heater under conditions in which it is difficult to secure a sufficient space in the engine room with the tendency of miniaturization and high efficiency, which may be a cause of hindering the miniaturization.
In particular, a cartridge heater using a Nichrome wire has a difficulty in controlling temperature, may be overheated when air is not ventilated to the heater side and may have an insulating problem and the risk of fire due to high voltage.
Further, an air conditioner for a vehicle using a positive temperature coefficient (PTC) heater is disclosed in Japanese Patent Application Publication No. 2009-255739 and the PTC heater according to the related art is illustrated in FIG. 1.
In FIG. 1, the flow direction of air is represented by an arrow and the PTC heater illustrated in FIG. 1 includes a heat source part 11 comprised of a PTC element, a heat radiating part 12 contacting the heat source part 11 and efficiently discharging heat, and a housing 20 enclosing and protecting a terminal part, the heat source part 11, and the heat radiating part 12.
The PTC heater according to the related art may have a slight difference in terms of the detailed configuration, but the heat source part is formed in parallel with the flow direction of air, such that the formation area of the heat source part directly affects the heat radiating performance, thereby having a limitation in reducing a thickness (in the flow direction of air) of the PTC.
In particular, in the case of the PTC heater, an electrical problem may occur when a heat radiating condition is poor. Therefore, the PTC heater needs to include a heat radiating part (generally, a heat radiating fin), such that a manufacturing and assembling process of the heat radiating part may be troublesome and the durability of the entire PTC heater may be degraded when heat is not effectively radiated.
Therefore, a need exists for the development of a heater which can increase the heat exchange efficiency to further improve the heating performance, be miniaturized and easily controlled, prevent the problems that may occur due to the overheating, and further improve the safety, by directly heating air while smoothing the flow of air.